DE2421903A1 - METHOD OF REGENERATING ALTOEL - Google Patents

Description

The invention relates to a new and improved method for regenerating used oil or waste oil, in particular from crankcases, do so to recover a greater proportion of this oil in such a form that it than Lubricant can be reused.

Eo is known that lubricants made from petroleum, such as oils for Kurbe-TgelEUse and the additives contained in them oxidize more or less rapidly depending on the conditions of use or otherwise dismantled and must be replaced with fresh oil at regular intervals. It's difficult one to dispose of such degraded oil without harming the air, land or water. Hence one has been around for many years Used oil regenerated from crankcases. Until now it has been far. · Extensive regeneration of the used oil is carried out with sulfuric acid, to remove the oxidized or degraded contaminants as ■ sludge. This was followed by a treatment of the oil with activated clay to remove the remaining coloring matter. The use of lubricating oils with particularly good properties

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shafts for engines but creates difficulties for this regeneration process. The wetting agents, the erosion preventers and the agents for improving the viscosity in these oils, the degradation products of these substances and the oil after use, create a sludge that does not easily coagulate with sulfuric acid. As a result, using this method, the oil must sometimes be treated with sulfuric acid twice or more in order to effectively remove the sludge. Since this process is uneconomical, many plants for regeneration are forced to stop their operation. This fact, together with the greater use of motor vehicles, and thus a greater ^{amount of A} .ofallö], create difficulties in keeping the environment clean which the waste oil is brought.

Other methods of regenerating waste oil have also been disclosed. According to U.S. Patent 1,842,933 the oil is treated with sulfuric acid, followed by an aqueous mixture of zinc chloride with sodium hydroxide or others Chemicals follows, and then the lubricating oil is separated by distillation. Under these conditions is Sodium zincate and not sodium chloride is the effective agent, because the sodium hydroxide with the zinc chloride to form Sodium zincate reacts. Further is the recovery of the oil very costly from the sludge by distillation. According to a second method according to US Pat. No. 3,417,012 an aqueous mixture of sulfuric acid, zinc chloride and

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if desired, added to other ingredients, followed by more Steps are taken to recover the regenerated oil. Untex "these conditions, zinc sulfate is the most effective agent and not zinc chloride, because the sulfuric acid displaces the chlorine in the form of hydrochloric acid "

These known methods use sulfuric acid and alkaline solutions. Here, there arises the difficulty of removing the dangerous corrosive sludge and the difficulty of poor filtration. Often times, because the sludge is colloidal, filtration is so difficult or impossible. This leads to yields of 30% or less. Therefore, the use of sulfuric acid and alkaline solutions is lend from the economic standpoint and in terms of the environment is not zufriedens.te7 _L,

The present invention avoids the difficulties associated with the known methods mentioned. It has been found that when anhydrous zinc chloride is used in effective amounts, satisfactory coagulation of the sludge in waste oils from crankcases is achieved and that no hazardous chemical additives are required under these anhydrous conditions. It is believed that the increased effectiveness of hot zinc chloride in the absence of water to coagulate sludge in used crankcase oil - as opposed to the prior art use of aqueous solutions - is related to the ability of the zinc chloride

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at about 25o ° C as a dehydrator, as a coagulant, to serve as a desulfurizing agent and as a flux for the removal of metal oxides such as lead oxide.

With the process of the invention, the use of the hazardous concentrated acid, caustic soda, or other chemicals is not necessary, and there are no difficulties in separating the oil from the acidic tars and sludges. These residues are difficult, dangerous and costly to remove. According to the process of the invention, all diluents, undesired sulfur-containing ingredients, sludges and other contaminants are de-purified. These components are quickly precipitated in the form of a dry sludge with the zinc chloride, which sludge is easy to handle and is not hazardous. The sludge containing the zinc chloride can be ^{burned at about 500 to 600 °} C., and the zinc can be recovered as zinc chloride or as zinc oxide. These can either be sold as marketable by-products or the zinc chloride can be fed back into the process.

The inventive method for regenerating waste oil, in particular of oil from crankcases consists in mixing the oil with about 3 to about 10% by weight of anhydrous zinc while stirring. chloride mixes, the mixture is quickly heated under reduced pressure so high and long enough that the impurities in the oil

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as steam and sludge accumulate that you can remove the supernatant oil from the Sludge is separated by mixing the separated supernatant oil with activated clay, that the mixture of the oil and the activated clay is heated rapidly with stirring, and that this mixture is heated under reduced pressure for as long as L, d33 the desired color is achieved in the finished oil. The oil is then separated from the clay containing sludge.

The process generally consists in mixing the used oil with a suitable amount of anhydrous zinc chloride, placing the mixture under reduced pressure, heating the mixture under reduced pressure as quickly as possible to remove the impurities apply the oil as a vapor and sludge that cooling the mixture and allowed to settle in that separates the excess oil from the sludge, that activated the separated oil clay is added, that this second mixture under reduced pressure brings _s that this mixture Heated under reduced pressure as quickly as possible, and long enough to achieve the desired coloration of the oil, and that the finished oil is then separated from the sludge containing the activated clay. The separation of the sludge in the first process step can be carried out in any way, for example by allowing the sludge to settle and decanting the partially refined oil, or by filtering or centrifuging. A vacuum filter can

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use satisfactorily for severing. The activated one Clay-containing sludge can be made from the end product in "any" Separated in a manner, e.g. using a Pilterrahmeri press.

The following examples illustrate some practical forms of the process _o

example 1

34 kg of used oil from a crankcase are pumped into a reaction vessel. At the same time 2 kg of anhydrous ":" Zinc chloride., Were added, unc / with constant stirring. After applying a Takuums of 550 mm Hg - column · the mixture as soon as possible heated to 25O ⁰ C and 20 minutes kept at this temperature.

The reaction products were then placed in an open drum, where they were allowed to cool and settle overnight. _<r> After decanting the supernatant oil from the sludge of the oil 10 percent, were -% activated clay was added and the mixture was returned to the reaction vessel. Under reduced pressure, the mixture .wurde as quickly as possible stirred and heated to 185 ⁰ C. After 20 minutes at −185 ° C., the reaction products were filtered off in a frame filter press. The amounts of substance used and incurred in two experiments in which this method was used are shown in Table 1 below. It should be noted that the

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"Distribution of the various factions can vary significantly of those shown in Table 1. This distribution is dependent the extent of contamination or degradation of the Waste oil. The properties of the regenerated oil are shown in Table-2. Besides the excellent properties of the oil according to Table 2, the oil exhibited no turbidity and no odor, as are often characteristic of regenerated ones Crankcase oils.

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Introduced substances

kg

TABEL

E9

Applied substances

kg

E8

E9

Implementation with zinc chloride

509 01 from the crank
casing
Zinc chloride 34.1
2.04 34.1
2.04 Distillates
Zinc sludge
partially refined oil
losses 3.14
9.44
21.64
1.92 3.05
9.32
23.53
0.24 I. co 36.14 36.14 36.14 36.14 Implementation with the
activated sound O O
co
co Partly refined oil
volume 20.66
2.07 22.82
2.29 Distillates
Refined oil and
Clay mud
losses 0.26
22.23
0.24 0.44
24.52
0.15 22.73 25.11 22.73 25.11 Filtration Refined oil + clay
containing sludge , 22.23 24.52 Containing sound
mud
Refined oil
losses 3.72
18.70 4.64
19.70
0.18 22.23 24.52 22.42 24.52

TABEL

E8 E9

Partly grooved oil ⁰ C 2.97 154 2.94 Neutralization number 138 200 104 Flash point according to Pensky-Marten 61.7 Refined oil 0.29 7.9 .0.33. Neutralization number ⁰ C 4th 103 L 4-1 / 2 coloring ⁰ C 0.15 133 Flash point according to Pensky-Marten CS 0.876 - a) Flash point according to the Cleveland
procedure CS 0.207 53.5 Viscosity at 38 ^° C 7.0 Viscosity at 100 ^° C Wt. -2ο 95.1 Viscosity index 0.025 * Sulfated ash - a) specific weight - a) Coal residue after
Conradson

a) not measured

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According to Example 1, the separation of the sludge from the partially refined oil after the reaction with the zinc chloride carried out by settling the sludge and decanting the partly refined oil. This settling happens slowly. To determine whether the mud is easily removed from the partially rafi nated oil can be separated by filtration - was the carried out the following experiment.

Example 2

6 g of anhydrous zinc chloride were added to 94 g of used oil from a crankcase. The G-einisch was stirred and bo quickly as possible to 25O ⁰ C under a pressure of 30 mm Hg. Heated. After a reaction time of about 20 minutes, the mixture was allowed to cool to about 80 ° C. and then filtered through a Buchner funnel - in which a filter cloth and.

an auxiliary filter had been placed. The Trkhbsr 7 was _o . *

held at 75 C and a pressure drop of 506 mm Eg.

maintained in the funnel. The mud drained quickly and completely separate from the partially refined oil by passing 110 ml of a clear filtrate through in less than 5 minutes passed through the funnel.

It should be noted that the cooling to BO ^ C and the nitriding at 75 ⁰ G are only carried out in order to simplify the experiment.

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Those skilled in the art will know that pre-cooling is not essential » and that in the case of filtration "at higher temperatures, the rate of filtration is increased because the viscosity of the partially raiELnierte oil is lowered here. Furthermore, it would not be necessary to add so much additional heat to the to spend the following implementation with the sound.

Although a batch process is described here, the process can also be carried out continuously by suitable dimensions and designs of the reaction vessel and the additional equipment. -

Numerous other attempts have also been made to examine the variables of the process and their influence on it determine the properties of the regenerated oil;

a) Concentration of anhydrous zinc chloride

b) the temperature of the reaction with the zinc chloride

c) the time required for the reaction with the zinc chloride

d) the vacuum when reacting with the zinc chloride

e) concentration of activated clay

f) the temperature during the reaction with the clay

g) the time to implement with the sound h) the vacuum during the reaction with the clay

The determined ranges for the variables of the method are contained in Table 3. They are given by practical means

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Considerations and technical circumstances. The purpose of use of anhydrous zinc chloride is that both the low-boiling impurities, which lead to an undesirable, result in a low flash point in the regenerated oil,

and the semi-solid or solid impurities that are also

.. / to be removed.

are undesirable in the regenerated 01, the purpose of the use The tone consists in removing the unwanted coloring substances that are not already with the sludge in the implementation with which zinc chloride has been removed. The attempts were made performed with used ÖD. from crankcases, the commercial regeneration was used, and they are as a result typical for waste oils that occur practically. In some cases, of course, used oils also come from crankcases that are more or less contaminated by low-boiling substances, by semi-solid or solid substances and by coloring substances,

TABLE 3

Variable of the process . area

1. Reaction with zinc chloride

a) Concentration of zinc chloride,% by weight 3 to 10

b) reaction ^{temperature, 0} C 150 to 290

c) Implementation time, min. 20 to 30

d) Absolute pressure, mm Hg - column 30 to 500

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TABLE 3 (continued)

Variable of the procedure area

2. Implementation with the sound

e) concentration of clay,% by weight 5 "to 15

f) reaction ^{temperature, 0} C 120 "to 235

g) Reaction time, min. 20 to 60 h) Absolute pressure, mm Hg - column 30 to 500

With the waste oil from crankcases that was used in the tests, has been in use τοη 3 wt .- ^ zinc chloride, an oil having a low flash point of 110 ⁰ C by Pensky-Marten obtained. The removal of the sludge was not complete, since Sch.la.mrn was obtained in an amount only twice the weight of the zinc chloride, compared to _ -. ·· about 5 times the amount of sludge, based on the same »weight of zinc chloride, according to Example 1. Used waste oil from crankcases with less impurities and treated with 3% by weight of zinc chloride would result in an acceptable oil, but waste oils with such low levels of impurities, which can be successfully treated with less than 3% by weight zinc chloride are seldom produced. Used oils from crankcases with such high levels of impurities that more than 10% by weight of zinc chloride are used produce too little regenerated oil and are therefore not economically viable.

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The amount of clay required for the removal of the coloring matter is similarly dependent on that Degree of contamination of the oil to be regenerated.

The initial temperature, the conversion time and the absolute Pressure in the reactions with the zinc chloride and the clay also influence the properties of the regenerated Oils of a type well known to those skilled in the art. The respective process conditions can change accordingly the extent of the contamination of the oil used. if For example, the oil to be regenerated contains very large amounts of a solvent or a gasoline as impurities , may it be necessary, a lower pressure or to use a longer duration in the implementation with the) zinc chlorid, than shown in Table 3. If the oil to be regenerated has very low levels of such impurities and Contains degradation products, it may be possible to have shorter conversion times to be used in the reactions with zinc chloride and clay, as Table 3 shows.

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Claims (9)

Claims 1. Process for regenerating waste oil, especially used oil Crankcase oils, characterized in that aas oil is mixed with about 3 to about 10 wt .- ^ anhydrous Zinc chloride mixes, the mixture quickly heated under reduced pressure so high and so long that the impurities incurred as steam and as sludge, the supernatant oil separates from the sludge, it tinter stirring with activated Clay mixes, the mix quickly under reduced pressure heated so high and long enough that the oil has obtained the desired color, and then the oil from which the clay containing sludge separates. 2. The method according to claim 1, characterized in that one the mixture of oil and zinc chloride is heated to about 175 to about 290 ° C
Temperature. 290 ° C and heat it for about 20 to 30 minutes at this 3. The method according to claim 1 or 2, characterized in that the separated oil containing zinc chloride is mixed with about 5 to about 15 wt .-% activated clay. 4. The method according to any one of claims 1 to 3, characterized in that that one that, mixture of oil and activated Heat clay to about 120 to about 235 ° C and hold it at that temperature for about 20 to about 60 minutes. E09827 / 0483 " ¹⁶ 2Λ21903 5. The method according to any one of claims 1 to 4, characterized in that that the supernatant oil is separated from the sludge by cooling, allowing it to settle and decanting. 6. The method according to any one of claims 1 to 4, characterized in that separating the supernatant oil from the sludge by filtration. 7. The method according to any one of claims 1 to 6, characterized in that that the mixture of oil and zinc chloride is heated under a pressure of about 30 to about 500 mm Hg column. 8. The method according to any one of claims 1 to 7, characterized in that that one column of the mixture of oil and activated clay under a pressure of about 30 to about 500 mm Hg heated. 9. Process for regenerating used crankcase oils, characterized by the following stages: * The used crankcase oil is 3 to 10 wt -% added anhydrous zinc chloride and the mixture stirred;. ^{the mixture is heated rapidly to 175 to 200 °} C. under an absolute pressure of 30 to 500 mm Hg column and kept under these conditions for 20 to 30 minutes; - 17 - 509827/0483 the supernatant oil is separated from the settled sludge, with 5 to 15 wt activated sound added and stirred; the mixture of oil and clay is placed under an absolute pressure of 30 to 500 mm Hg column heated to a temperature of 120 to 135 ° C and under these conditions for 20 to 60 minutes held; finally the oil is separated from the clay sludge, 5 09 827/048 3